So you invent a wireless network using LEDs, what do you do next? Add solar panels. Boom

Ingenious Scottish boffins have invented a solar-panel-powered version of their data networking kit that uses light to shift bits wirelessly. The team, based at the University of Edinburgh, first called its technology D-Light, short for data light, and its existence was revealed exclusively by your humble correspondent during …

[Trevor_Pott]

Zoiks. Over 1Gbit. I remember going this with infrared LEDs and photodiodes when I was in elementary. Built a widget that could do 2400 baud reliably, and eventually got it up to 9600 baud with rather a lot of work. Trying to get the network to go from upstairs where the modem was down to my bedroom. Devilish lot of work that was*, so I've nothing but respect for these chaps. Well done.

*of course, I was like 8, so this might seem somewhat easier to modern day me. Still, don't know as I could exactly design the thing from memory anymore. Research. With books. Dear gods how times have changed...

[Geoff Campbell]

"Professor Harald Haas, who came up with the Li-Fi idea"

In the mid '80s, Apricot were using LEDs to communicate from keyboard to PC, and Research Machines were using them for data communication between machines. No doubt there were plenty of other examples, too.

Then there's the whole "data down an optical fibre from pulsed LEDs" thing that powers just about all modern communications worldwide.

Remind me again, what did Haas come up with?

GJC

[Anonymous Coward]

Re: "Professor Harald Haas, who came up with the Li-Fi idea"

This is slightly different but you're right, Apricot did come up with it and I'm sure I saw it on Tomorrow's World too (but that may have been Apricot)

[Peter Simpson 1]

Re: "Professor Harald Haas, who came up with the Li-Fi idea"

Meh...it's been done:

http://www.cbronline.com/news/bicc_claims_infralan_as_first_standard_wireless_network_for_token_ring

// barely worked at 16Mbit/s, IIRC

[Anonymous Coward]

Fantastic.

This will really help all those folks out in the middle of nowhere with normal/slow DSL broadband.

If you kit it out with megawatt lasers and a footy field sized solar array...

Other than that, whats the point??

[DainB]

Re: Fantastic.

Not so fast, where's Internet comes from in the middle of nowhere and if it is already there why can't you plug wifi hotspot into whatever powers existing data transmission channels ?

[Charles 9]

Re: Fantastic.

1) Relay it from some corner of civilisation.

2) Hotspot uses too much power.

[Scott Broukell]

Smoke and mirrors!

Is that how one hacks these new networks?

[Anonymous Coward]

Inherently uni-directional

Inherently uni-directional, thus a waste of time. Plus that website listing all the fake possible applications is an embarrassment. Glasgow uni wouldn't put out gumf like that.

[Anonymous Coward]

Re: Inherently uni-directional

Downvoted, because there are plenty of applications where unidirectionality is acceptable. Think of TV & radio for starters.

[Stuart Castle]

Re: Inherently uni-directional

Actually, bi directional. So, by your definition, Microwave links and Laser communications must also be a waste of time. After all, both methods are also bi directional.

[Michael H.F. Wilkinson]

Hi-Tech Heliograph.

Neat in itself, but I remember the problems somebody had whenever he put a cuppa in front of his Apricot keyboard, blocking the line of sight between keyboard and computer. The key idea behind fibre optics is that you protect the optical path from intrusion by smoke and mirror. WIFI works better because the long wavelengths diffract around objects rather better than visible light or IR.

In conclusion, though the data rate obtained is good, I am slightly underwhelmed.

[Professor Clifton Shallot]

Re: Hi-Tech Heliograph.

"though the data rate obtained is good, I am slightly underwhelmed."

Particularly given the short distance that rate is available over.

There's something attractive about a robust, solar-powered data transfer mechanism - that sounds like it could be cheap and simple, and therefore useful - but if you have to have a node every 10m or so that all breaks down quite quickly.

[John Brown (no body)]

Re: Hi-Tech Heliograph.

"Neat in itself, but I remember the problems somebody had whenever he put a cuppa in front of his Apricot keyboard, blocking the line of sight between keyboard and computer."

Maybe he should have used the fibre link cable supplied free with every unit for those situations such as obstructed line-of-sight or bright sunshine. Or just read the instructions that came with it.

[EddieD]

The bbc did this before

The micro-computer program presented by Ian McNaught-Davis used to send programs out by a flashing dot in the corner of the screen which you read with a light pen.

[Tom 7]

Not as dumb as it sounds

at less than a watt bidirectional with a bit of effort (simple lightguides) range should be increased to several hundred meters for something that can use a small solar cell to charge batteries and run night and day all for probably less than $20.

Speed increases should be easy but I do most of my web browsing in the comfort of my beanbag in a nice room with cobb walls and 1Mb as a result - so long as I dont watch mostly pointless video I'm fine.

Not new but at 1/2 watt more than bloody useful.

[Christian Berger]

Re: Not as dumb as it sounds

I believe you are overestimating the possibilities here.

Fast speeds require special LEDs plus low multipath situations. You cannot simply put a lens in front of it and hope to get by with diffuse light... and still hope for a Gigabit. At such low ranges radio is much more competitive and needs much less power since you don't need to drone against that high intensity noise source in the sky.

The 'market' (I know an ugly word) for this is like the one of NFC. It's for communicating with something over <1m distances, for example for having "location based services".

Light is cheap for low data rates and short ranges, but once you want higher ranges and/or faster data rates, it's a different kind of animal.

[Pen-y-gors]

Another plus point

...no leakage and so better security. So long as you've got line of sight (not too tricky to arrange) you can use it to connect multiple devices within a room, but with no danger of your LiFi being slurped by a passing Googlemobile or general ne'er-do-well.

[John Smith 19]

Oh, it's a *light bulb* comms channel.

This dates back at least as far as PARC's "ubiquitous computing" idea of "plaques" and tablets linked by an IR network in every room. Back then they were looking at IrDA data rates but one must move with the times.

The key benefit seems to be LED ceiling lights already exist as trasnmitters so no new holes in the ceiling (although you'll have to run the data cables to them and add the power modulating hardware).

Historically this has been tried with flourecents with "smart ballasts" and the killer app is believed to be the near real time up date of price labels on the edges of supermarket shelves (which is a real PITA for large supermarkets) if the price/complexity/reliability problem can be solved.

Which so far it has not. So no instant offers "for 1 hour only" moving along the aisles.

BTW didn't "Ionica" have a go at line of sight wireless broadband some years ago in the UK? I think they went titsup.

If this thing has a really unique benefit I can't see it.

[TRT]

Re: Oh, it's a *light bulb* comms channel.

eInk labels on the shelf-edge?

[John Smith 19]

The smart pricing label.

"eInk labels on the shelf-edge?"

Probably. But now that's taken care of you've got the hard parts.

a)Eliminate battery replacements (the stores don't want to do it, even it's every 5 years and no, you can't wire the shelves, it limits their freedom to change the layout)

b)Minimize the additional wiring to individual lamps (ideally 1 chunk of hardware doing all the lamps at once).

People have chased this idea "on and off" so to speak for decades and AFAIK no one has fielded a system that lasts.

I'll suggest a few pointers. a)You can't expect total commitment from day 1, so the system has to cope with transisitonal situations of trial and partial fitouts of shops. b)I'd suggest the protocol support a "delayed display" mode so all the labels are updated and a signal (or time stamp) switches them all simultaneously c)As more shops go 24 hours don't rely on a "down time" period for recharging, updateing etc.

It may seem a trivial application but to make it work (and work profitably) calls for very high grade multi disciplinary engineering skillls.

OTOH the market is (potetially) every large shop in the world.

[Anonymous Coward]

Professor Haas's next invention

The chocolate teapot.

Line of sight wifi is a dead duck.

[Anonymous Coward]

Re: Professor Haas's next invention

CARVIONICS

Well line of sight Wi-Fi - in a town/road-traffic/motorway situation - with Li-Fi enabled LED streetlamps would be pretty useful for advanced traffic-routing, emergency updates & generic internet/Cbeebies to the iPad/avionics in the car. Vehicle just needs a 'shark's fin' light-receiver - tho' might have 360 coverage by having sensors front/back/sides/underneath - and would be able to talk back to the gigabit Street-Lights with a 50 megabit/s request channel.

NSA

Could also do Li-Fi P2P & M2M with all the other cars around. Even possible to do a store & forward packet relay service (like old UUCP mail/newsgroups) to get a non-snooped decentralised ad-hoc mesh network going, imagine your data travelling at 70mph up the M60?

[Anonymous Coward]

Re: Professor Haas's next invention @AC

Better hope the council pull their finger out and clean those street lamp LEDs once in a while. There are serious practical issues with Li-Fi

Lenses get dirty, ask any glasses wearer.

[Nick Ryan]

Interesting, however it is a struggle to see how it compares with other wireless technologies for many applications.

On the other hand, if you have a few sensors that can be put in awkward places and don't want to or can't run cables around but have sunlight available then you have a remote sensor that powers itself. It's line of sight, which may be a problem for some applications but for many sensor systems this wouldn't be a problem and the uni-directional nature will make it a little more efficient on the power over distance front.

[Anonymous Coward]

???

Am I the only one thinking that a network using light to communicate that needs a bright day to operate is slightly counter-intuitive?

[ForthIsNotDead]

Erm...

"a few days ago the Li-Fi team announced it can transfer data at 1.1Gbps using light from micro LEDs over a distance of 10 metres, all while using less than 0.5W power – which is low enough for a solar panel to drive"

Or you could, you know, use a LAN cable...

[P. Lee]

Re: Erm...

> Or you could, you know, use a LAN cable...

Yes, that would give you full duplex too. However, think about an enclosed space without precise electrical contacts - e.g. put a phone on a charging cradle and a little LED in the cradle talks to the phone - no breakable USB cable connection (or RJ45 clip / optical connector) required, no interference from the wireless charging device.

Or my favourite idea - magsafe-type network connectors. No need for precision laser fibre connections, just an LED and a receiver in a reasonable dark little box.

[WonkoTheSane]

Monty Python has "Prior Art"

Ladies & Gentlemen, I give you "Julius Ceasar on an Aldis Lamp".

http://www.youtube.com/watch?v=yLWUSka0HOw‎

[~mico]

IrDA

Speed: 2.4 kbit/s to 1 Gbit/s

http://en.wikipedia.org/wiki/Infrared_Data_Association

What did he invent again?

Can I please file a patent on wheel? Please?

[Rick Giles]

And this data frame here...

..causes every one in the vicinity to have a seizure...

[steve 124]

Scotland? Really?

So, let me get this straight... You're experimenting with "solar powered" "line of sight" data transmission that requires clear air... in Scotland... Does anyone else see a problem here?

I'm a Yank and admittedly the only things I know about grand old Scotland is what I've seen on TV and the internet but I get the distinct impression that there are two things Scotland has a shortage of, namely, sunlight and clear sunny days. This seems like a project best suited for a more arid climate. Just sayin.

[Adam T]

Clacks

I'm sure it's a great piece of technology, but why put LEDs every ten meters when you can have a perfectly eco-friendly Clacks tower every ten hundred meters?

[Will Godfrey]

This has whiskers

I remember an article in Practical Wireless around the middle 1960s where they were modulating a neon indicator as the transmitter, and sensing with an OC71 transistor with the paint scraped off. They used car headlamp reflectors as (nearly) parabolic mirrors. This was not for data, but audio with a bandwidth of something like 10kHz.

Never did get round to trying it myself.

[Buck Fukdaman]

Really!?

Everyone is so blinded by the benefits of the status quo, thanks to a service provider near you..? Dost thou really not comprehend the fact that (sub)urban networks have much more than enough 'connectability' as is necessary for point-to-point (as well as a mixed topology) 'secure' transmissions at around a ten meter distance per peer..? Silly me...

All hail the glorious AT&T, BT, Comcast, etc!

I must be foolish to think that well educated consumers could possibly decide for themselves what is important regarding communication with trusted peers...

And you want to add an off-grid, low-power, renewable energy source into the mix!?

You must be mad!!

[Brandon 2]

i'm so lazy...

If only they could use this technology to allow me to remotely change channels on my TV... er... wait.. I don't have a TV.

[proud2bgrumpy]

A waste of research time?

If the primary application of this is 3rd world networking, then couldn't this be done more simply and using fewer and less complicated / much cheaper resources with LAN cables. If it is for wider distances (>20m) then its not appropriate anyway. If it is for offices/stores or homes by replacing light fittings with data/LEDs bulbs, then any advantage of having an existing light fitting to place your emitter is lost by having to lay the new data cables - especially in domestic homes - maybe less of a problem in offices/stores.

I really don't see what problem this will address that isn't already solved amply by some variant of Wired/WIFI/NFC solutions. Still funds often gets pi**ed away on apparently useless research projects - like that other light amplification by stimulated emission of radiation project - huh! where did that ever get to...